The assignment had been expected since the start of spring training. Tracy said he waited until the day after Jimenez had a strong start to make it official. He pitched three scoreless innings Tuesday against the Los Angeles Dodgers.

Aaron Cook, who started for the Rockies on Opening Day in 2007 and 2009, said he wanted to be with Tracy when he gave the news to Jimenez. Tracy said Cook "very unselfishly is handing the torch to him."

"I have a lot of respect for (Cook), but right now I have even more respect for what he did, that he came in with us," Jimenez said of the meeting with Tracy. "After Tracy told us, we walked outside and he gave me a lot of advice about Opening Day. He told me to just take it as another game and be prepared for it and just enjoy it."

This will be the first Opening Day start for the 26-year-old Jimenez, who went 15-12 last year with a 3.47 ERA, the lowest in franchise history for a starter. While logging 218 innings, Jimenez pitched at least six in a franchise-record 25 consecutive starts from May 1-Sept. 7.

"I like challenges," Jimenez said. "I'll be there."

Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

To report corrections and clarifications, contact Reader Editor Brent Jones. For publication consideration in the newspaper, send comments to letters@usatoday.com. Include name, phone number, city and state for verification.

Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more.